And a little more than one month later, the first IDE kits have been assembled and tested. Actually, four out of seven participants finished soldering our kits two-three weeks ago, but nobody has bothered to test their interface.
Tonight, we brought a 48K ZX Spectrum to the "course", and a portable TV. The TV didn't work well with RF input, so the Spectrum was quickly modified to output composite video instead. It seems the hack is so simple that Sinclair could've put a toggle switch on the side and had the computer output both RF and composite from the factory. Perhaps they would've done it if composite output had been common in 1982.
My IDE interface and one more, both assembled by us die-hard Commodore freaks, worked out of the box. The third interface, built by a Sinclair fan, didn't boot up to his great despair. The fourth student didn't show up, so it is uncertain whether his kit is working or not. The final three who yet are not done will have to wait and see.
Now, I need to get me a ZX Spectrum, now that I have cool hardware for it. Or perhaps sell the assembled IDE interface. For the summer/fall term, we are again considering Replica 1, at least the few of us who can justify the price. There are a number of ideas about kits, repair projects etc, so we'll figure out something to do.